[css-cascade-6] Fix errors after including '@import' section

 - Ambiguous 'display' property.
 - Adjustments to oldids.
 - Proper link form for 'supports query'.

Author: andruud

css-cascade-6/Overview.bs

@@ -35,6 +35,7 @@ spec:selectors-4; type:dfn; text:selector
 spec:selectors-4; type:dfn; text:combinator
 spec:html; type:element; text:style
 spec:css-scoping-1; type:dfn; text:shadow host
+spec:css-display-4; type:property; text:display
 </pre>
 
 <pre class=ignored-specs>
@@ -43,7 +44,7 @@ spec:css-values-4
 spec:css-fonts-4
 </pre>
 
-<h2 id="intro" oldids='filtering,fragments,stages-examples,actual,used,computed,cascaded,declared,specified,value-stages,all-shorthand,aliasing,shorthand,content-type,import-processing,conditional-import,at-import,defaulting,initial-values,inheriting,defaulting-keywords,initial,inherit,inherit-initial,default'>
+<h2 id="intro" oldids='filtering,fragments,stages-examples,actual,used,computed,cascaded,declared,specified,value-stages,all-shorthand,aliasing,shorthand,defaulting,initial-values,inheriting,defaulting-keywords,initial,inherit,inherit-initial,default,layer-empty'>
 Introduction and Missing Sections</h2>
 
 	Issue: This is a diff spec over <a href="https://www.w3.org/TR/css-cascade-5/">CSS Cascading and Inheritance Level 5</a>.
@@ -192,7 +193,7 @@ Conditional ''@import'' Rules</h3>
 
 	The [=import conditions=] are given by
 	<<media-query-list>>, which is parsed and interpreted as a <a>media query list</a>,
-	and <<supports-condition>>, is parsed and interpreted as a [[supports query]].
+	and <<supports-condition>>, is parsed and interpreted as a [=supports query=].
 	If a <<declaration>> is given in place of a <<supports-condition>>,
 	it must be interpreted as a <<supports-decl>>
 	(i.e. the extra set of parentheses is implied)